围填海工程建于软土地基上,海堤易产生不规则沉降甚至坍塌,而在高水位期间可能发生溃堤灾害。本文采用HLL逼近Riemann解格式计算界面通量和有限体积法离散控制方程建立了数学模型,对围填海工程溃堤洪水运动进行模拟研究。针对浙南某围填海工程,成功模拟了海塘不同位置发生溃堤时的洪水演进过程:溃堤初始时刻,围区内淹没面积和淹没水深增长迅速,其后洪水推进速度放缓,平均水深则经历下降、快速增长、缓慢增长3个阶段变化,并且南堤溃决事故下同时刻平均水深较东堤溃决时高0.3~0.5 m,其洪水灾害性和风险性更高。进一步分析双溃口条件下淹没水深的空间分布及其变化规律可知,洪水完全淹没围填海区仅需要60min,溃堤4h后淹没水深可达1.7 m,围区东、南部两股水流迅速交汇将会造成较大的人员伤亡,其他区域居民可有15 min以上逃生时间。另外,糙率参数在土15%区间变化下,计算平均水深最大变幅为20%,淹没面积最大变幅为14%。研究成果对于减少溃堤突发事故损失,提高工程建设管理水平具有重要现实意义,可为今后围填海工程的安全设计和风险评估提供技术依据。
Abstract
Study on sea dikes breaching flood of the reclamation was carried out by means of numerical simulation in this thesis. The numerical model was based on the finite volume algorithm, which applied the HLI approximate Riemann solver to compute the numerical flux. A computational case study was presented of the flooding in a reclamation project of Zhejiang,where the flooded area and depth varying with time were obtained. The boundary condition of sea dikes breaching flow was taken by a constant water level, which is 20-year high tide level combined with the same frequency maximum wave height under the most unfavorable conditions. The model simulated the flooding in different locations of sea dikes failure successfully and the result shows that the submerged area and submerged depth rises quickly at the beginning of sea dikes breaching, and then the advance speed of flood tends to slow down,the average depth is followed by three stages of development: a slight decline, a dramatic rise and a small increase. The average depth for the south dike breaching flood is higher than that under the east dike-break case by 0.3~0.5 m at the same moment, so is the catastrophe and risk. The movement of flood caused by double breaching locations was further analysed. The flood spends only 60 minutes to overwhelm the reclamation, and the submerged depth rises to l.7 m after 4 hours. In the southeast, the convergence area between two sea dikes breaching flow, heavy personnel casualty will be caused, but the people in the rest area will have 15 minutes to escape the flood. In addition,the impact of roughness range from plus 15 per cent to minus 15 per cent on the flood was discussed. It is concluded that the differences between the maximum and minimum of average depth and submerged area reached 20 and 14 percent, respectively. This research will be of great practical significance to reduce the loss of sea dikes breaching accident as well as raise the management standard in the construction period and running period, which aims to provide the base of safety design and risk assessment of reclamation project.
关键词
围填海 /
海塘溃决 /
洪水演进 /
数学模型
Key words
reclamation /
sea dikes breaching /
flood /
mathematical model
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] ZHANG Xing-nan, ZHANG Wen-ting, LIU Yong-zhi, et al.Simulation models of flood inundation due to storm tide[J]. Journal of System Simulation, 2006 , 18:20-23.
张行南,张文婷,刘永志,等.风暴潮洪水淹没计算模型研究[J].系统仿真学报, 2006,18:20-23.
[2] WANG Weir biao. Study on risk analysis and safety evaluation of seawall on Qiantang River[D]. Hangzhou: Zhejiang University, 2005.
王卫标. 钱塘江海塘风险分析和安全评估研究[D].杭州:浙江大学, 2005.
[3] ZHU Jun-zheng, XU You-cheng.Study on the calamity and counter-measure of the super ty phoon storm surge along the Zhe-jiang coastal area[J]. Journal of Marine Sciences, 2009 ,27(2): 104-110.
朱军政,徐有成.浙江沿海超强台风风暴潮灾害的影响及其对策[J].海洋学研究,2009,27(2):104-110.
[4] YAN Sheng.Study on safety measuers of northern seawalls in Qiantang River under the storm surges over design[D]. Hang-zhou: Zhejiang University , 2010.
严盛. 超标准风暴潮作用下的钱塘江北岸海塘安全措施研究[D]. 杭州:浙江大学,2010.
[5] HARTEN A.High resolution schemes for hyperbolic conservation laws[J]. Journal of Computation Physics,1 983 , 49 :357-393.
[6] WANG Jia-song, NI Han-gen, JIN Sheng, et al.Simulation of 1 D dam break flood wave routing and reflection by using TVD schemes[J]. Journal of Hydraulic Engineering,1998 , 29(5) :1-5.
王嘉松,倪汉根,金生,等.用TVD显隐格式模拟一.维溃坝洪水波的演进与反射[J].水利学报,1998 ,29(5):1-5.
[7] GODUNOV S K.Finite difference method for the computation of discontinuous solutions of the equations of fluid dynamics[J]. Math Sbornik, 1959 ,47:271-306.
[8] BAI Lu-hai, JIN Sheng.Study on high resolution scheme for shal-low water equation with source terms[J]. Journal of Hydrody-namics:Ser. A, 2009 ,24(1): 305-312.
柏禄海,金生.带源项浅水方程的高阶格式研究[J].水动力学研究与进展:A辑,2009 ,24(1):305-312.
[9] WANG Kun, JIN Sheng,MA Zhi-qiang, et al.On a well-bal-anced discretization scheme for two-dimensional shallow water equations with source terms[J]. Journal of Hydrodynamics: Ser. A,2009, 24(5) : 535-542.
王昆,金生,马志强,等.基于和谐性离散格式求解带源项的二维浅水方程[J].水动力学研究与进展:A辑,2009 ,24(5) :535-542.
[10] YING X Y, KHAN A A, WANG SS Y.Upwind conservative scheme for the Saint Venant Equations[J]. Journal of Hydraulic Engineering , 2004 , 130(10) :977-987.
[11] OSHER S, SOLOMON F.Upwind difference schemes for hy-perbolic conservation laws[J]. Math Comp, 1982,158: 339-374.
[12] HE Zhi-guo, WU Gang-feng,WANG Zhen-yu, et al.Numerical simulation for dam-break flood in hurricane-prone regions[J]. Journal of Zhejiang University: Engineering Science, 2010, 44: 1 589-1 596.
贺治国,吴钢锋,王振宇,等.台风暴雨影响区域的溃坝洪水演进数值计算[J].浙江大学学报:工学版,2010,44:1589-1 596.
[13] HARTEN A,LAX P D, VAN LEER B.On upstream differencing and Godunov-type schemes for hyperbolic conservation laws[J]. SIAM Review, 1983.25(1) :35-61.
基金
浙江省重大专项基金资助( 2009C03008-1)
PDF(3136 KB)
